60 
EASTERN SHADE TREE CONFERENCE 
Results. The Federal work program as amplified by New York 
State’s efforts has given the following results: 
1. East of the Hudson River in the heavily infected zone of 1934, the 
incidence of the disease has been reduced annually by 30 per cent to 40 
per cent; but to the north in upper Westchester, Putnam and Dutchess 
Counties the area of light infection has greatly increased in size and the 
numbers of diseased elms have increased annually throughout this area. 
2. West of the Hudson River, adjacent to the heavily infected terri¬ 
tory in New Jersey and with local swamp problems of considerable 
magnitude, the incidence has not been reduced below the 1935 figure 
and the lightly infected territory to the north covering most of Orange 
County has slowly increased in size and numbers of diseased elms 
annually. 
The known infected area in New York State over which scouting for 
diseased elms and sanitation for bark beetle material must be done each 
year has increased as follows: 1144 square miles in 1934, 1402 in 1935, 
1706 in 1936, 1867 in 1937 and 2460 in 1938. These figures show 
the failure of the eradication program to prevent the disease from 
spreading into increasingly larger territory. 
In other respects, however, the eradication program has shown re¬ 
sults that are highly encouraging. For example, in both the heavily 
infected and lightly infected zone east of the Hudson River it is defi¬ 
nitely demonstrated that prompt removal of the diseased elms and local 
sanitation will prevent recurrence of the disease in the immediate vicin¬ 
ity. 
This is shown by the results in New York City with an area of 300 
square miles and an estimated population of 50,000 elms over 5 inches, 
where the incidence has been reduced as follows: from 1320 diseased 
elms in 1934, to 627 in 1935, to 269 in 1936, to 128 in 1937 and 61 in 
1938. This past summer no diseased elms were found in Manhattan 
and Brooklyn and only 3 were found in Queens. The drop to 21 dis¬ 
eased elms on Staten Island in 1938 from 716 in 1934 in an estimated 
population of 10,000 elms over 5 inches, and the reduction from 465 in 
1934 in the Bronx to 36 in 1938 in an elm population of at least 20,000, 
shows the effectiveness of the eradication method. The 61 diseased 
elms found this year in New York City represent a loss of only about 
one-tenth of one per cent of the estimated number of elms over 5 inches 
which gives a high rating to the eradication method as a control measure. 
North of New York City in the residential area of lower Westchester 
